Slip-ring-less three-phase alternators are known (see, for example, German Patent Disclosure Document DE OS No. 29 35 929). Such alternators use a magnetic field generating element, current through which may be controlled, for example by a voltage regulator, which is stationary; an armature winding is located concentric with the field. The field generating element is coupled through a narrow air gap with a flux guide element, for example in form of a claw pole structure which, alternately, presents North and South Poles to the stationary armature. Thus, the only portion which is rotating is a flux guide element, so that the field structure can be directly connected to the voltage regulator. In such alternators, for example as disclosed in the German Patent Disclosure Document referred to, the shaft which secures the flux guide element is mounted in a first ball bearing which is positioned within an end plate of the alternator, for example adjacent to a drive pulley; a second ball bearing is mounted in a second bearing plate which, typically, is cup-shaped. The space between the flux guide and available within the cup-shaped second bearing plate may be used to support rectifier diodes and accessory electrical equipment to provide direct current output to a vehicle battery. The armature lamination stack is clamped between the first and second bearing plate, and held under radial and axial tension.